The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines draw air into an intake manifold through an inlet that may be regulated by a throttle. The air may also be pressurized and forced into the intake manifold by a compressor (part of a turbocharger). The air in the intake manifold is distributed to a plurality of cylinders and combined with fuel to create an air/fuel (A/F) mixture. In compression ignition (CI) engines (e.g., diesel engines), for example, the pistons compress the air within the cylinders. Fuel may then be combined with (i.e., injected into) the compressed air causing the pressurized A/F mixture to combust.
The combustion of the A/F mixture drives pistons which rotatably turn a crankshaft generating drive torque. The drive torque may be transferred from the crankshaft to a driveline (e.g., wheels) of a vehicle via a transmission. Exhaust gas produced during combustion may be expelled from the cylinders into an exhaust manifold. The exhaust gas may include carbon monoxide (CO) and hydrocarbons (HC). The exhaust gas may also include nitrogen oxides (NOx) due to the higher combustion temperatures of CI engines compared to spark ignition (SI) engines. The exhaust manifold may be connected to one or more systems that receive the exhaust gas. For example, the exhaust gas may be routed to an exhaust treatment system, an exhaust gas recirculation (EGR) system, and/or a turbine system.